From patchwork Mon Sep 28 16:03:10 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gabriele Paoloni X-Patchwork-Id: 523379 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 92D1B140549 for ; Tue, 29 Sep 2015 01:56:29 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934211AbbI1P42 (ORCPT ); Mon, 28 Sep 2015 11:56:28 -0400 Received: from szxga03-in.huawei.com ([119.145.14.66]:16797 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934119AbbI1P42 (ORCPT ); Mon, 28 Sep 2015 11:56:28 -0400 Received: from 172.24.1.47 (EHLO szxeml434-hub.china.huawei.com) ([172.24.1.47]) by szxrg03-dlp.huawei.com (MOS 4.4.3-GA FastPath queued) with ESMTP id BOC37805; Mon, 28 Sep 2015 23:56:18 +0800 (CST) Received: from localhost.localdomain (10.67.212.75) by szxeml434-hub.china.huawei.com (10.82.67.225) with Microsoft SMTP Server id 14.3.235.1; Mon, 28 Sep 2015 23:56:08 +0800 From: Gabriele Paoloni To: , , CC: , , , , , , , Subject: [PATCH v2 ] PCI: Designware: make num-lanes an optional DT property Date: Tue, 29 Sep 2015 00:03:10 +0800 Message-ID: <1443456190-225875-1-git-send-email-gabriele.paoloni@huawei.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 X-Originating-IP: [10.67.212.75] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020204.56096329.014E, ss=1, re=0.000, recu=0.000, reip=0.000, cl=1, cld=1, fgs=0, ip=0.0.0.0, so=2013-05-26 15:14:31, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 374b18215fff5db0352eabaf61158171 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: gabriele paoloni Currently num-lanes is read in dw_pcie_host_init(). For a SoC that performs the link-up operation in UEFI, num-lanes is not needed in the DTS; however currently it has to be specified to some random value otherwise dw_pcie_host_init will fail. If the link is brought up in BIOS dw_pcie_setup_rc should not be called. This patch reworks dw_pcie_host_init() so that, if num-lanes is not specified, it sets pp->lanes = 0. If later on dw_pcie_setup_rc is called and pp->num_lanes is not set to a valid value, dw_pcie_setup_rc will send an error message and return. This patch is a follow-up of http://www.spinics.net/lists/linux-pci/msg44394.html Signed-off-by: Gabriele Paoloni --- Documentation/devicetree/bindings/pci/designware-pcie.txt | 3 ++- drivers/pci/host/pcie-designware.c | 10 ++++++---- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt index 9f4faa8..0036ab3 100644 --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt @@ -14,7 +14,6 @@ Required properties: - interrupt-map-mask and interrupt-map: standard PCI properties to define the mapping of the PCIe interface to interrupt numbers. -- num-lanes: number of lanes to use - clocks: Must contain an entry for each entry in clock-names. See ../clocks/clock-bindings.txt for details. - clock-names: Must include the following entries: @@ -22,6 +21,8 @@ Required properties: - "pcie_bus" Optional properties: +- num-lanes: number of lanes to use (this property should be specified unless + the link is brought already up in BIOS) - reset-gpio: gpio pin number of power good signal - bus-range: PCI bus numbers covered (it is recommended for new devicetrees to specify this property, to keep backwards compatibility a range of 0x00-0xff diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index 52aa6e3..047ac52 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -482,10 +482,9 @@ int dw_pcie_host_init(struct pcie_port *pp) } } - if (of_property_read_u32(np, "num-lanes", &pp->lanes)) { - dev_err(pp->dev, "Failed to parse the number of lanes\n"); - return -EINVAL; - } + ret = of_property_read_u32(np, "num-lanes", &pp->lanes); + if (ret) + pp->lanes = 0; if (IS_ENABLED(CONFIG_PCI_MSI)) { if (!pp->ops->msi_host_init) { @@ -764,6 +763,9 @@ void dw_pcie_setup_rc(struct pcie_port *pp) case 8: val |= PORT_LINK_MODE_8_LANES; break; + default: + dev_err(pp->dev, "num-lanes = %u: invalid value\n", pp->lanes); + return; } dw_pcie_writel_rc(pp, val, PCIE_PORT_LINK_CONTROL);